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<h1 class="title">flowlayout.cpp 示例文件</h1>
<span class="subtitle">layouts/flowlayout/flowlayout.cpp</span>
<!-- $$$layouts/flowlayout/flowlayout.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
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  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  <span class="preprocessor">#include &lt;QtWidgets&gt;</span>

  <span class="preprocessor">#include &quot;flowlayout.h&quot;</span>
  FlowLayout<span class="operator">::</span>FlowLayout(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent<span class="operator">,</span> <span class="type">int</span> margin<span class="operator">,</span> <span class="type">int</span> hSpacing<span class="operator">,</span> <span class="type">int</span> vSpacing)
      : <span class="type"><a href="qlayout.html">QLayout</a></span>(parent)<span class="operator">,</span> m_hSpace(hSpacing)<span class="operator">,</span> m_vSpace(vSpacing)
  {
      setContentsMargins(margin<span class="operator">,</span> margin<span class="operator">,</span> margin<span class="operator">,</span> margin);
  }

  FlowLayout<span class="operator">::</span>FlowLayout(<span class="type">int</span> margin<span class="operator">,</span> <span class="type">int</span> hSpacing<span class="operator">,</span> <span class="type">int</span> vSpacing)
      : m_hSpace(hSpacing)<span class="operator">,</span> m_vSpace(vSpacing)
  {
      setContentsMargins(margin<span class="operator">,</span> margin<span class="operator">,</span> margin<span class="operator">,</span> margin);
  }

  FlowLayout<span class="operator">::</span><span class="operator">~</span>FlowLayout()
  {
      <span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>item;
      <span class="keyword">while</span> ((item <span class="operator">=</span> takeAt(<span class="number">0</span>)))
          <span class="keyword">delete</span> item;
  }

  <span class="type">void</span> FlowLayout<span class="operator">::</span>addItem(<span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>item)
  {
      itemList<span class="operator">.</span>append(item);
  }

  <span class="type">int</span> FlowLayout<span class="operator">::</span>horizontalSpacing() <span class="keyword">const</span>
  {
      <span class="keyword">if</span> (m_hSpace <span class="operator">&gt;</span><span class="operator">=</span> <span class="number">0</span>) {
          <span class="keyword">return</span> m_hSpace;
      } <span class="keyword">else</span> {
          <span class="keyword">return</span> smartSpacing(<span class="type"><a href="qstyle.html">QStyle</a></span><span class="operator">::</span>PM_LayoutHorizontalSpacing);
      }
  }

  <span class="type">int</span> FlowLayout<span class="operator">::</span>verticalSpacing() <span class="keyword">const</span>
  {
      <span class="keyword">if</span> (m_vSpace <span class="operator">&gt;</span><span class="operator">=</span> <span class="number">0</span>) {
          <span class="keyword">return</span> m_vSpace;
      } <span class="keyword">else</span> {
          <span class="keyword">return</span> smartSpacing(<span class="type"><a href="qstyle.html">QStyle</a></span><span class="operator">::</span>PM_LayoutVerticalSpacing);
      }
  }

  <span class="type">int</span> FlowLayout<span class="operator">::</span>count() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> itemList<span class="operator">.</span>size();
  }

  <span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>FlowLayout<span class="operator">::</span>itemAt(<span class="type">int</span> index) <span class="keyword">const</span>
  {
      <span class="keyword">return</span> itemList<span class="operator">.</span>value(index);
  }

  <span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>FlowLayout<span class="operator">::</span>takeAt(<span class="type">int</span> index)
  {
      <span class="keyword">if</span> (index <span class="operator">&gt;</span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&amp;</span><span class="operator">&amp;</span> index <span class="operator">&lt;</span> itemList<span class="operator">.</span>size())
          <span class="keyword">return</span> itemList<span class="operator">.</span>takeAt(index);
      <span class="keyword">else</span>
          <span class="keyword">return</span> <span class="number">0</span>;
  }

  <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Orientations FlowLayout<span class="operator">::</span>expandingDirections() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> <span class="number">0</span>;
  }

  bool FlowLayout<span class="operator">::</span>hasHeightForWidth() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> <span class="keyword">true</span>;
  }

  <span class="type">int</span> FlowLayout<span class="operator">::</span>heightForWidth(<span class="type">int</span> width) <span class="keyword">const</span>
  {
      <span class="type">int</span> height <span class="operator">=</span> doLayout(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> width<span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> <span class="keyword">true</span>);
      <span class="keyword">return</span> height;
  }

  <span class="type">void</span> FlowLayout<span class="operator">::</span>setGeometry(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> <span class="operator">&amp;</span>rect)
  {
      <span class="type"><a href="qlayout.html">QLayout</a></span><span class="operator">::</span>setGeometry(rect);
      doLayout(rect<span class="operator">,</span> <span class="keyword">false</span>);
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> FlowLayout<span class="operator">::</span>sizeHint() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> minimumSize();
  }

  <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> FlowLayout<span class="operator">::</span>minimumSize() <span class="keyword">const</span>
  {
      <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> size;
      <span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>item;
      foreach (item<span class="operator">,</span> itemList)
          size <span class="operator">=</span> size<span class="operator">.</span>expandedTo(item<span class="operator">-</span><span class="operator">&gt;</span>minimumSize());

      size <span class="operator">+</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qsize.html">QSize</a></span>(<span class="number">2</span><span class="operator">*</span>margin()<span class="operator">,</span> <span class="number">2</span><span class="operator">*</span>margin());
      <span class="keyword">return</span> size;
  }

  <span class="type">int</span> FlowLayout<span class="operator">::</span>doLayout(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> <span class="operator">&amp;</span>rect<span class="operator">,</span> bool testOnly) <span class="keyword">const</span>
  {
      <span class="type">int</span> left<span class="operator">,</span> top<span class="operator">,</span> right<span class="operator">,</span> bottom;
      getContentsMargins(<span class="operator">&amp;</span>left<span class="operator">,</span> <span class="operator">&amp;</span>top<span class="operator">,</span> <span class="operator">&amp;</span>right<span class="operator">,</span> <span class="operator">&amp;</span>bottom);
      <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> effectiveRect <span class="operator">=</span> rect<span class="operator">.</span>adjusted(<span class="operator">+</span>left<span class="operator">,</span> <span class="operator">+</span>top<span class="operator">,</span> <span class="operator">-</span>right<span class="operator">,</span> <span class="operator">-</span>bottom);
      <span class="type">int</span> x <span class="operator">=</span> effectiveRect<span class="operator">.</span>x();
      <span class="type">int</span> y <span class="operator">=</span> effectiveRect<span class="operator">.</span>y();
      <span class="type">int</span> lineHeight <span class="operator">=</span> <span class="number">0</span>;

      <span class="type"><a href="qlayoutitem.html">QLayoutItem</a></span> <span class="operator">*</span>item;
      foreach (item<span class="operator">,</span> itemList) {
          <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>wid <span class="operator">=</span> item<span class="operator">-</span><span class="operator">&gt;</span>widget();
          <span class="type">int</span> spaceX <span class="operator">=</span> horizontalSpacing();
          <span class="keyword">if</span> (spaceX <span class="operator">=</span><span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>)
              spaceX <span class="operator">=</span> wid<span class="operator">-</span><span class="operator">&gt;</span>style()<span class="operator">-</span><span class="operator">&gt;</span>layoutSpacing(
                  <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>PushButton<span class="operator">,</span> <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>PushButton<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Horizontal);
          <span class="type">int</span> spaceY <span class="operator">=</span> verticalSpacing();
          <span class="keyword">if</span> (spaceY <span class="operator">=</span><span class="operator">=</span> <span class="operator">-</span><span class="number">1</span>)
              spaceY <span class="operator">=</span> wid<span class="operator">-</span><span class="operator">&gt;</span>style()<span class="operator">-</span><span class="operator">&gt;</span>layoutSpacing(
                  <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>PushButton<span class="operator">,</span> <span class="type"><a href="qsizepolicy.html">QSizePolicy</a></span><span class="operator">::</span>PushButton<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Vertical);
          <span class="type">int</span> nextX <span class="operator">=</span> x <span class="operator">+</span> item<span class="operator">-</span><span class="operator">&gt;</span>sizeHint()<span class="operator">.</span>width() <span class="operator">+</span> spaceX;
          <span class="keyword">if</span> (nextX <span class="operator">-</span> spaceX <span class="operator">&gt;</span> effectiveRect<span class="operator">.</span>right() <span class="operator">&amp;</span><span class="operator">&amp;</span> lineHeight <span class="operator">&gt;</span> <span class="number">0</span>) {
              x <span class="operator">=</span> effectiveRect<span class="operator">.</span>x();
              y <span class="operator">=</span> y <span class="operator">+</span> lineHeight <span class="operator">+</span> spaceY;
              nextX <span class="operator">=</span> x <span class="operator">+</span> item<span class="operator">-</span><span class="operator">&gt;</span>sizeHint()<span class="operator">.</span>width() <span class="operator">+</span> spaceX;
              lineHeight <span class="operator">=</span> <span class="number">0</span>;
          }

          <span class="keyword">if</span> (<span class="operator">!</span>testOnly)
              item<span class="operator">-</span><span class="operator">&gt;</span>setGeometry(<span class="type"><a href="../qtcore/qrect.html">QRect</a></span>(<span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(x<span class="operator">,</span> y)<span class="operator">,</span> item<span class="operator">-</span><span class="operator">&gt;</span>sizeHint()));

          x <span class="operator">=</span> nextX;
          lineHeight <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMax">qMax</a>(lineHeight<span class="operator">,</span> item<span class="operator">-</span><span class="operator">&gt;</span>sizeHint()<span class="operator">.</span>height());
      }
      <span class="keyword">return</span> y <span class="operator">+</span> lineHeight <span class="operator">-</span> rect<span class="operator">.</span>y() <span class="operator">+</span> bottom;
  }
  <span class="type">int</span> FlowLayout<span class="operator">::</span>smartSpacing(<span class="type"><a href="qstyle.html">QStyle</a></span><span class="operator">::</span>PixelMetric pm) <span class="keyword">const</span>
  {
      <span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">&gt;</span>parent();
      <span class="keyword">if</span> (<span class="operator">!</span>parent) {
          <span class="keyword">return</span> <span class="operator">-</span><span class="number">1</span>;
      } <span class="keyword">else</span> <span class="keyword">if</span> (parent<span class="operator">-</span><span class="operator">&gt;</span>isWidgetType()) {
          <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>pw <span class="operator">=</span> <span class="keyword">static_cast</span><span class="operator">&lt;</span><span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span><span class="operator">&gt;</span>(parent);
          <span class="keyword">return</span> pw<span class="operator">-</span><span class="operator">&gt;</span>style()<span class="operator">-</span><span class="operator">&gt;</span>pixelMetric(pm<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> pw);
      } <span class="keyword">else</span> {
          <span class="keyword">return</span> <span class="keyword">static_cast</span><span class="operator">&lt;</span><span class="type"><a href="qlayout.html">QLayout</a></span> <span class="operator">*</span><span class="operator">&gt;</span>(parent)<span class="operator">-</span><span class="operator">&gt;</span>spacing();
      }
  }

</pre>
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<!-- @@@layouts/flowlayout/flowlayout.cpp -->
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